Disengaging means for automatic control systems for aircraft



Oct. 10, 1939. L ETAL I 2,175,627

DISENGAGING mans FOR AUTOMATIC CONTROL SYSTEMS FOR AIRCRAFT Filed June11, 1958 2 Sheets-Sheet 1 1%YENTOR.

ATTORNEY.

Oct. 10, 1939. 5 l L E1- AL 2,175,627

DlSENGAGING MEANS FOR AUTOMATIC CONTROL SYSTEMS FOR AIRCRAFT Filed June11, 1938 2 Sheets-Sheet 2 INVENTORS Edward F/Iscbe/ BY Gem/d ff/elh X;ATTORNEY.

Patented Oct. 10, 1939 UNITED STATES DISENGAGING MEANS FOR AUTOMATICCONTROL SYSTEMS FOR AIRCRAFT Eduard Fischel, Berlin-Charlottenburg, andGerald Klein, Berlin-Dahlem, Germany, assignors to Siemens Apparate undMaschinen Gesellschaft mit bcschrankter Haftung, Germany, a corporationof Germany Berlin,

Application June 11, 1938', Serial No. 213,301

In Germany June 12, 1937 6 Claims.

for aircraft to interpose between the device and the control surfacesconnected thereto suitable clutch means for selectively engaging ordisengaging the device, and also an emergency coupling which may rapidlyand positively disconnect the entire apparatus from said surfaces. Indevices heretofore proposed of this character, both the clutch andemergency coupling have been governed by separate control means.

One of the objects of the present invention is to provide novel means ofthe above character wherein both a clutch and a coupling may be governedby a common control member.

Another object is to provide novel means of the above character forgoverning the order vof the action of a clutch and a disconnectingcoupling. v

A further object is to provide novel means of the above characterwherein a clutch and an emergency coupling may be rapidly disengaged 25in the order named by a thrust acting in one diretion.

The above and further objects and novel features will more fully appearfrom the following detailed description when the same is read in 30connection with the accompanying drawings. It is to be expresslyunderstood, however, that the drawings are for purposes of illustrationonly and are not intended as a definition of the limits of theinvention, reference for this latter purpose- Fig. 5 is a sideelevation, partly in section, of,

the invention; 50 Fig. 6 is a side elevation, partly in section and withparts broken away, of a second embodiment of the invention;

Fig. 7 is a side elevation of the emergency coupling; and

Fig. 8 is a section taken on the line 8-8 of 5 Fig. 7.

The form of the invention illustrated in the accompanying drawings, byway of example, is a device for governing from a common control memberboth a clutch and an emergency cou- 10 pling which are interposedbetween an automatic pilot apparatus and a control surface for anaircraft. The clutch member comprises a conventional magnetic devicewhich, when deenergized, permits the transmission of torsional moments.15 The emergency coupling is a mechanical device which may beconstituted by a suitable latch coupling. A common control member isprovided for the clutch and coupTng which is adapted for both angularand longitudinal displacement. 20 Means are associated therewith whichenergize or deenergize the magnetic coupling as the control member isangularly shifted and which disconnect the mechanical coupling when themember is longitudinally withdrawn from an initial position.

In Fig. 1, a servo-motor (not shown), for example, of an automatic pilotapparatus is connected to a shaft i0 which is connected through aconventional selectively engageable and disengageable magnetic clutch IIto a shaft l2. Clutch II is connected through leads Ila, Ilb upon anelectro-magnet I3 forming a part thereof, to a suitable source of energyand to a switch to appear later. Shaft I2 is operatively connected to acontrol surface I by means of a rod Ha operatively connected to anemergency coupling i5 which may be of the type disclosed in thecopending application of Hans Werner Tiebel,

- Serial No. 171,342, filed October 2'7, 1937, and

comprising two levers which are both angularly shiftable about the axisof shaft l2. One of these levers it (see Figs. 7 and 8) is keyed toshaft i2 between the parts of the second lever comprising a pair offirmly connected parallel I arms lid and Ill; and which are pivotallymounted upon shaft i2. These levers are interconnected by means of alatch I! which is pivotally mounted by journals Ila and llb upon the sec0nd lever and adapted for engaging a toothed vgitudinal and rotarymovements.

portion |6a of lever l6. An arm I9 is attached to shaft |9a connected toone of the journals |8b by which the latch is pivotally mounted whereby'the latch may be disengaged by angularly shifting said arm by means ofa wire 20 attached to the free extremity thereof;

An embodiment of the common or joint control member for both couplingsis shown in Figs. 2 to 5. The control member is constituted by a switchhaving a shaft 2| within a housing 22 which has an end covering 23through which shaft 2| extends. A handle 24 is rigidly secured to theextending portion of said shaft and is provided with a pointer 24a whichis adapted for indicating the angular positions of the shaft, i. e., theon and "off positions, against suitable fixed markings 23b, 2311,respectively, upon the covering 23. Shaft 2| is adapted for bothlongitudinal and angular displacement in housing 22 and is securedagainst unintentional longitudinal displacement by a groove lockcomprising a ball 25 which, under pressure of a spring 26, engages anannular groove 21 upon said shaft. Mounted upon shaft 2| is a switchlever 28 which is provided with a key 28a engaging a longitudinal grooveor keyway 2 a in the shaft. Lever 28, therefore, may transmit onlyrotary movements and not longitudinal movements ofthe shaft, said leverbeing prevented from moving longitudinally by sleeves 22a, 22b ofhousing 22. Rotatably mounted between a bifurcated extremity of lever 28is a roller 29 which upon rotation of shaft 2| is engageable with abifurcated extremity of an arm 30 which controls an electric switch SIfor the magnet l3 of clutchl To an extremity of shaft 2| which extendsthrough the rear of housing 22, the wire 20 is attached by means of acap nut 32. Between the off" and "on positions illustrated, anintermediate or "stand-by position (not shown) may be provided. Thehandle must be moved at first from the off into the stand-by positionwhen, for example, the power means or the servo-motor for governing thecontrol surface is energized, or the navigation instruments necessaryfor the automatic control system are placed in operation. The clutch maythen be closed'by movement to the on" position.

In operation, if the control surface I4 is being controlled by anautomatic apparatus which is connected to shaft l and it is desired todisengage temporarily said apparatus, the handle 24 is moved from the onposition to the position as shown in Fig. 2 A turning moment istransmitted to lever 28 by shaft 2| and hence to arm 30 which actuates aswitch which, in turn, energizes electromagnet l3 and disengages clutchThe reverse of this process, of course, will reengage the clutch. If thepilot is forced, due to failure of the automatic control system, toplace the latter out of operation in order to avoid a dangeroussituation, the handle 24 is pulled outwardly. The longitudinaldisplacement of shaft 2| will, by means of wire 20, trip the latch ofthe emergency coupling l and disengage same thus freeing the controlsurface.

In apparatus of this type, it may be desirable, in order to facilitate aquicker disengagement, that both the clutch and coupling be disengagedby a single movement, i. e., movement in a single direction, rather thanby a combination of ion- This rapid disengagement should beaccomplished, preferably such that; the clutch and coupling bedisengaged in the order named. This is accomplished in the embodimentshown in Fig. 6 which is identical to that of Figs. 2 to 5 with theexception that a. keyway 2| b, analogous to keyway' 2|a, instead ofbeing straight is cut in the form of a helix, i. e., a screw thread.

In the operation of this embodiment, if it becomes necessary in anemergency to free the control surface immediately, the handle 24 beingin the on" position is pulled outwardly. The screw action of the helicalkeyway 2|b causes lever 28 to be angularly shifted to move arm 30 and todisengage clutch H. Immediately thereafter the longitudinal displacementof shaft 2| will disengage coupling l5 and complete the disconnection ofthe control surface.

There is thus provided a novel common control member for a combinationclutch and coupling. The device may be rapidly operated by a singlemovement and requires no concentration and very little thought in orderto successfully actuate the same. The apparatus is positive inoperationand provides a common manually operable member for selectivelyactuating either said clutch or coupling.

Although only two embodiments of the invention are illustrated anddescribed in detail, it is to be expressly understood that the inventionis not limited thereto; for example, there have been selected for use inassociation with the invention, a magnetic and a mechanical coupling.However, any other suitable types of couplings may be employed. Variouschanges may also be made in the design and arrangement of the parts without departing from the spirit and scope of the invention, as the samewill now be understood by those skilled in the art. For a definition ofthe limits of the invention, reference will be had primarily to theappended claims.

What is claimed is:

1. The combination with a selectively engageable and disengageableclutch of an emergency coupling, common means for selectively actuatingeither said clutch or said coupling, said means being adapted fordisengaging both clutch and coupling, in the order named, by adisplacement thereof in a single direction.

2. In apparatus of the class described, a clutch, a coupling, a controlmember having a shaft adapted for both longitudinal and angulardisplacement, said member including means for actuating said clutch bysaid angular displacement, and means for actuating said coupling by saidlongitudinal displacement.

3. The combination with a clutch and a coupling of a common controldevice therefor comprising a manually operable longitudinally andangularly displaceable member, means for disengaging both said clutchand coupling when said member is longitudinally displaced, said meansbeing adapted for actuating only said clutch when said member isangularly displaced.

4. The combination with a clutch and a coupling of alever operativelyconnected to said clutch, said lever being mounted upon a longitudinallydisplaceable and angularly shiftable shaft, the latter being operativelyconnected to said coupling, and means for yieldingly retaining saidshaft in a predetermined position.

5. The combination with a clutch and a coupling of a shaft having ahelical keyway, a lever mounted upon said shaft having a key fitting insaid keyway, said shaft being adapted for both angular and longitudinaldisplacement, means for operatively connecting said lever and saidclutch, and means operable when said shaft is longitudinally displacedfor disengaging said coupling.

6. In apparatus of the class described, a clutch,

a coupling, common control means therefor comprising a shaft adapted forlongitudinal and angular displacement, means for actuating said

